Wall Thickness and Rotational Molding Design

Wall Thickness - Rotational Molding Design
Wall Thickness - Rotational Molding Design

Rotational molding design requires close attention to more than just functional requirements, material and processing limitations, and production costs. As we learned in the overview to this series, the details of a part’s design can make the difference between success and failure.  No matter what your rotomolding application, you’ll need to follow some best practices regarding wall thickness.

Why Wall Thickness Matters

Wall thickness is important because the wall defines the plastic part’s basic shape. In fact, the wall or frame may be the most important part detail because of its relationship to other decisions. For example, the wall thickness of a part determines the amount of material that’s required. Wall thickness also has a direct effect on part costs and cycle times.

Wall thickness affects part strength, but thicker walls aren’t the only way to design stronger plastic parts. As a rotomolding company with over 70 years of experience, Gregstrom can provide your engineering team with advice about designing walls that offer the same or greater strength, but that use less material. To learn more about ribs, kiss-offs, and other techniques for added part strength, please contact us.

Wall Thickness and Rotomolding Advantages

Compared to other manufacturing methods for plastic parts, rotational molding offers important advantages in terms of wall thickness. Specifically, rotomolding lets designers increase or decrease the thickness of the part wall after the mold has been build and sampled. Finalizing the wall thickness can even wait until after in-use testing. Other plastics manufacturing methods just don’t offer this flexibility.

Relative to their size, rotomolded parts can have thinner walls than similar parts than are produced by other plastic manufacturing methods. Unlike blow molding, a process that tends to produce thin outside corners, rotomolding tends to produce an increasing wall thickness on the outside corner of parts. In large parts especially, this added thickness and increased strength at the outside corners is an advantage.

Ask Gregstrom for Rotational Molding Design Assistance

Gregstrom Corporation of Woburn, Massachusetts (USA) provides plastic contract manufacturing services that include design assistance, rotational molding, and plastic parts finishing. In our next blog entry about rotational molding design, we’ll examine wall thickness uniformity and varying wall thicknesses. Until then, please contact us to request a quote or learn about our rotational molding capabilities.